This invention relates to bonding compositions and bondable articles utilizing such compositions. More particularly, this invention relates to a bonding composition containing a crystalline polyester material and an amorphous polyester material and a bondable magnet wire having coated thereon such a bonding composition.
A variety of applications exist for bonding compositions. One such application has been the bonding of insulated or magnet wire conductors in various uses. Among such uses are transformers, lift magnets, solenoids, bobbinless coils, clutch coils, television yoke coils and field coils for stationary and rotating windings. In recent years there has been disclosed various thermoplastic compositions for coating the insulated wire during manufacture and thereafter at the time of fabrication into the desired configuration, such as that of a coil, bonding the coated wires by such means as heating or use of a solvent or a combination of both. In the field of magnet wire, an insulated wire conductor with an additional coating of thermoplastic bonding composition is commonly referred to as a self-bonding or bondable magnet wire.
There is a definite requirement in applications, such as motor applications, for a more thermally stable bonding material, that is, a material that bonds at a relatively low temperature, exhibits good bond strength at normal or room temperature and retains bond strength at relatively elevated temperatures. As can be appreciated, a bonding composition which can be bonded at relatively low temperatures (below about 180.degree. C.) and still retain an appreciable bond strength at temperatures as high as 200.degree. C. or higher would represent an advancement in or a contribution to this art. Such would be particularly advantageous if the mechanical, electrical and thermal properties of the magnet wire were maintained.